1. Technical Field
The present invention relates to controller systems for controlling powered apparatus and more particularly to a chin actuated controller system for controlling powered apparatus.
2. Discussion of the Prior Art
Quadriplegic persons, such as those suffering from high spinal chord injury, are often able to operate a powered apparatus which may be a powered wheelchair, if the apparatus is equipped with a chain actuated controller system, whereby the occupant controls or commands desired operation of the wheelchair by means of slight chin movements. Various mechanisms have been proposed in the prior art for permitting a quandriplegic person to operate a powered apparatus. For example U.S. Pat. No. 4,078,627 discloses essentially a joystick whose end is equipped with an enlarged rubber cup, designed to fit over and engage the patient's chin. The joystick is then moved relative to its central position by the patient's chin movements, e.g. forward and back in order to select forward and reverse directions of travel respectively, with speed dependent upon the amount of displacement of the joystick from its central position, and proportionate steering control being accomplished by chin movement of the joystick to the left or right of center. This conventional joystick-type chin controller is rather bulky in design and is objectionable for some users in that it remains positioned in front of the user's face until removed by an attendant.
Another prior art mechanism is that disclosed in the applicant's prior U.S. Pat. No. 4,260,035 which is also assigned to the assignee of applicant's present invention. In the applicant's prior patent there is provided a chin controller system having an elongated control arm which extends unobtrusively to a location adjacent to the occupant's chin and there supports a low profile actuator mechanism. Depression of the actuator provides proportional speed control of the wheelchair. In addition, lateral movement of the actuator from side-to-side in a horizontal plane provides proportional left/right steering control of the wheelchair.
The chin controller disclosed in applicant's prior U.S. Pat. No. 4,260,035, was clinically evaluated and the following situations where encountered. The prior controller was subject to damage by the patient or attendant. In addition, the prior controller did not permit the wheelchair to remain stationary and spin about its vertical axis. Even further the prior controller did not allow for the inadvertent change in the patient's position.